Cuculus is a genus of cuckoo

Cuckoo

The cuckoos are a family, Cuculidae, of near passerine birds. The order Cuculiformes, in addition to the cuckoos, also includes the turacos . Some zoologists and taxonomists have also included the unique Hoatzin in the Cuculiformes, but its taxonomy remains in dispute...

s which has representatives in most of the Old World

Old World

The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....

, although the greatest diversity is in tropical southern and southeastern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

. The species in taxonomic order are:

• Sulawesi Cuckoo or Sulawesi Hawk-cuckoo, Cuculus crassirostris
• Large Hawk-Cuckoo
  Large Hawk-cuckoo
  The Large Hawk-Cuckoo is a species of cuckoo in the Cuculidae family.They call in summer and the goes on well after dusk....
  
  , Cuculus sparverioides
  • Dark Hawk-Cuckoo, Cuculus (sparverioides) bocki
• Common Hawk-Cuckoo
  Common Hawk-cuckoo
  The Common Hawk-Cuckoo , popularly known as the Brainfever bird, is a medium sized cuckoo resident in South Asia. It bears a close resemblance to the Shikra, a sparrow hawk, even in its style of flying and landing on a perch...
  
  , Cuculus varius
• Moustached Hawk-Cuckoo
  Moustached Hawk-cuckoo
  The Moustached Hawk-Cuckoo is a species of cuckoo in the Cuculidae family.It is found in Brunei, Indonesia, Laos, Malaysia, Myanmar, and Thailand.Its natural habitat is subtropical or tropical moist lowland forests....
  
  , Cuculus vagans
• Hodgson's Hawk-Cuckoo
  Hodgson's Hawk-cuckoo
  The Hodgson's Hawk-Cuckoo, Cuculus fugax is a species of cuckoo found in south, east and southeast Asia.Hodgson's Hawk-Cuckoo is a brood parasite. The chick evicts bona fide residents of the parasitized nest, thus becoming the sole occupant. Under normal circumstances, this would reduce the...
  
  , Cuculus fugax
  • Malaysian Hawk-Cuckoo, Cucuclus (fugax) fugax
  • Hodgson's Hawk-Cuckoo, Cuculus (fugax) nisicolor
  • Rufous Hawk-Cuckoo, Cuculus (fugax) hyperythrus
• Philippine Hawk-Cuckoo
  Philippine Hawk-cuckoo
  The Philippine Hawk-Cuckoo is a bird belonging to the cuckoo family. It is found only in the Philippines. It was formerly classified as a subspecies of Hodgson's Hawk-Cuckoo but is now commonly treated as a separate species based on differences in vocalizations.It is a medium-sized cuckoo, about...
  
  , Cuculus pectoralis
• Red-chested Cuckoo
  Red-chested Cuckoo
  The Red-chested Cuckoo is a species of cuckoo in the Cuculidae family. It is a medium-sized bird , found in Africa south of the Sahara.-Distribution and habitat:...
  
  , Cuculus solitarius
• Black Cuckoo
  Black Cuckoo
  The Black Cuckoo is a species of cuckoo in the Cuculidae family. The species is distributed widely across sub-Saharan Africa...
  
  , Cuculus clamosus
• Indian Cuckoo
  Indian Cuckoo
  The Indian Cuckoo is a member of the cuckoo order of birds, the Cuculiformes, that is found in Asia from Pakistan and India, Sri Lanka east to Indonesia and north to China and Russia. It is a solitary and shy bird, found in forests and open woodland at up to 3,600 m.-Description:This is a medium...
  
  , Cuculus micropterus
• Common Cuckoo
  Common Cuckoo
  The Common Cuckoo is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals....
  
  , Cuculus canorus
• African Cuckoo
  African Cuckoo
  The African Cuckoo is a species of cuckoo in the Cuculidae family.It is found in Angola, Benin, Botswana, Burkina Faso, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Côte d'Ivoire, Djibouti, Eritrea, Ethiopia, Gabon, Gambia, Ghana,...
  
  , Cuculus gularis
• Himalayan Cuckoo, Cuculus saturatus
• Oriental Cuckoo
  Oriental Cuckoo
  The Himalayan Cuckoo is a species of cuckoo in the genus Cuculus. It breeds from the Himalayas eastward to southern China and Taiwan. It migrates to southeast Asia and the Greater Sunda Islands for the winter....
  
  , Cuculus optatus (formerly horsfieldi)
• Sunda Cuckoo
  Sunda Cuckoo
  The Sunda Cuckoo or Sunda Lesser Cuckoo is a South-east Asian bird belonging to the genus Cuculus in the cuckoo family, Cuculidae. It was formerly classified with the Himalayan Cuckoo and Oriental Cuckoo in a single species, C...
  
  , Cuculus lepidus
• Lesser Cuckoo
  Lesser Cuckoo
  The Lesser Cuckoo is a species of cuckoo in the Cuculidae family.It is found in Bangladesh, Bhutan, China, Democratic Republic of the Congo, Hong Kong, India, Japan, Kenya, North Korea, South Korea, Laos, Malawi, Myanmar, Nepal, Pakistan, Russia, Seychelles, Somalia, South Africa, Sri Lanka,...
  
  , Cuculus poliocephalus
• Madagascar Cuckoo
  Madagascar Cuckoo
  The Madagascar Cuckoo , also known as the Madagascar Lesser Cuckoo, is a species of cuckoo in the Cuculidae family. Though it breeds only in Madagascar, it spends the non-breeding season in a number of East African countries: Burundi, Democratic Republic of the Congo, Madagascar, Malawi, Rwanda,...
  
  , Cuculus rochii
• Pallid Cuckoo
  Pallid Cuckoo
  The Pallid Cuckoo is a species of cuckoo in the Cuculidae family.It is found in Australia, Christmas Island, Indonesia, New Zealand, and Papua New Guinea....
  
  , Cuculus pallidus

The hawk-cuckoos are sometimes placed in a separate genus, Hierococcyx, while the Pallid Cuckoo may belong in Cacomantis

Cacomantis

Cacomantis is a genus of cuckoo in the Cuculidae family. The genus name is derived from the Greek kakos meaning evil or ill-boding and mantis for prophet and is derived from their association with "rains" being supposed to be predict ill fortune and bad weather. Most of them have a round nostril...

.

These bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s are of variable size with slender bodies, long tails and strong legs. Most occur in open forests, but some prefer more open country. Several species are migratory

Bird migration

Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...

.

These are vocal species, with persistent and loud calls. They feed on large insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, with hairy caterpillar

Caterpillar

Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...

s, which are distasteful to many birds, being a speciality. One or two species will also take some fruit.

Cuculus cuckoos are brood parasite

Brood parasite

Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...

s, that is, they lay a single egg in the nests of various passerine

Passerine

A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

 hosts. The best-known example is the European Common Cuckoo

Common Cuckoo

The Common Cuckoo is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals....

. The female cuckoo in each case replaces one of the host’s eggs with one of her own. The cuckoo egg hatches earlier than the host’s, and the chick grows faster; in most cases the cuckoo chick evicts the eggs or young of the host species.

Cuculus species lay coloured eggs to match those of their passerine

Passerine

A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...

hosts. Female cuckoos specialise in a particular host species (generally the species that raised them) and lay eggs that closely resemble the eggs of that host.

A species may consist of several gentes, with each gens specialising in a particular host. There is some evidence that the gentes are genetically different from one another though other authorities state that as female cuckoos mate with males of any gens, genes flow between gentes.